The automobile is a very important means of transportation in our lives, which has contributed to the rapid development of the automobile industry and the growth of automobile ownership. Many consumers often pay more attention to the vehicle's shape, power, fuel consumption and other factors when buying a car, but little is known about the anti-corrosion ability of the car. This has led to those who have bought a car with sufficient "face engineering" and have not used it long Corrosion of the vehicle will occur in time, which will seriously affect your own experience of using the car, and even more serious will lead to traffic accidents.
The body's corrosion resistance has always been an important concern in the industry, and zinc-aluminum-magnesium coating products are also considered as the next-generation automotive protective coating materials. In this issue, we interviewed Mr. Gao Yongsheng, chief technical expert of Shougang Co., and talked with us about the application progress and product research of zinc-aluminum-magnesium-coated automotive panels.
Gao Yongsheng, chief technical expert of Shougang Co., Ltd.
I. New generation of protective coating materials for automobiles
At present, zinc-aluminum-magnesium coating (ZM) has been widely used in cold-formed automotive steel products. In addition to cold-formed steel plates, zinc-aluminum-magnesium coatings on hot-formed steel plates are also feasible.
Compared with the traditional protective coating materials for automobiles-pure zinc coating (GI) and alloyed coating (GA), the advantages of zinc-aluminum-magnesium coatings are manifested in three aspects: first, the coatings have excellent plane and cut protection. Take the neutral salt spray test as an example, the time of red rust on the surface of the zinc-aluminum-magnesium coating of the same weight is 2 to 5 times that of the traditional coating surface, and the time of red rust on the cut is 4 to 7 times that of the traditional coating. ; Second, the zinc-aluminum-magnesium coating has excellent surface friction and abrasion resistance. The surface hardness is 2 to 3 times that of pure zinc coatings and about 2 times that of alloyed coatings. The surface friction coefficient is 10% lower than the above two coatings. 20%, the amount of coating wear and peel is reduced by 30% to 70% under the same stamping conditions; third, the galvanic corrosion effect of the zinc-aluminum-magnesium-plated steel plate connected with non-ferrous metals is lighter.
Cyclic corrosion test
The corrosion resistance of Zn-Al-Mg coatings is about 4 times that of pure zinc coatings and alloy coatings.
The development and application of new products has always been a process of breaking the old and establishing new ones, especially the brand-new products cannot be separated from the coordination and support of the industrial chain.
Second, the optimized performance of corrosion resistance, friction resistance, compatibility
Zinc-aluminum-magnesium coated steel sheet not only has outstanding corrosion resistance and friction resistance, but also has good compatibility. From the research results of mainstream foreign automobile factories and Shougang, the spot welding characteristics, laser welding characteristics, and phosphating electrophoretic coating characteristics of zinc-aluminum-magnesium-coated steel plates are very different from traditional coatings, and there is no fundamental difference in production process. Optimization within the controllable range can meet the requirements, and does not constitute a strangeness in the application of new products.
At present, zinc-aluminum-magnesium-coated automotive panels have been widely used in foreign countries, especially in European automobile factories. Major domestic automotive companies are conducting research and trials, and believe that there will be greater progress in the near future. At present, the following three problems need to be resolved in the large-scale industrial application of zinc-aluminum-magnesium coated automotive panels:
First, the coating has not yet formed a universal national level standard. Different auto companies and steel companies have their own corporate standards. They have their own unique requirements for the coating, which hinders large-scale industrialization. Second, the coating is Domestic products are still new. At the national level, there are major special research projects supported by the Ministry of Science and Technology to support basic research funding, but there are still lack of corresponding supporting demonstration projects at the local level and in the industry field, and research funding at the application level is relatively lacking. The new coating has not yet formed a widespread response among the vast number of technical personnel in the automotive field, and there is still a lack of product support in various related industries, making it difficult to turn product advantages into value advantages.
Research Status of Shougang Automotive Steel Products
Since the successful development of zinc-aluminum-magnesium coating products in the 1980s, from the initial application of architectural color coatings to the current automotive applications, there have been more than two decades of development history. Since Shougang has produced automotive steel products, Has been tracking the latest research progress of this product, and has carried out long-term basic research work in the laboratory. He has mastered the production technology and product characteristics of zinc-aluminum-magnesium coatings with a variety of alloy composition ratios, and has overcome many productions such as alloy composition blending. Difficulties, successfully developed a series of zinc-aluminum-magnesium coating products.
Shougang Co., Ltd. is one of the representative enterprises of the production of high-quality steel products in China, and auto sheet is one of the three strategic products. Shougang is committed to investing more research and development resources in the field of ultra-high-strength automotive panels. At the same time, it is involved in the development of users' models in advance to provide EVI complete solutions. At the same time, Shougang also pays attention to the research and development of product standards, and has presided over the drafting of six national standards for automotive steels such as automotive duplex steel, hot stamped steel, and reinforced dual-phase steel. Shougang always adheres to the market-oriented and customer-centric development concept, strives to create a brand advantage of "intelligent manufacturing, service, and win-win", and focuses on promoting independent innovation around coated products, high-strength steel and automotive exterior panels to realize products R & D changes from following to leading.
In recent years, in order to meet the needs of automobile OEMs to reduce costs, improve quality and increase efficiency, Shougang has targeted the development of new varieties of outer panels, and its representative products are high-reflective, non-coated outer panels to reduce the manufacturing of automotive users. Process cost to achieve green manufacturing; a new generation of stamping and corrosion-resistant zinc-aluminum-magnesium coating products (ZM), leading the new exploration of automotive materials, highlighting comprehensive features such as easy stamping, corrosion resistance, and good process mold compatibility; The largest number of dual-phase steels for body materials. In order to meet the needs of high strength and complex forming, the first new product of reinforced plastic dual-phase steel (DH) was launched in China, which has been widely praised by many car companies.
Expert Information:
Dr. Gao Yongsheng received his Ph.D. in Engineering from the School of Mechanical Engineering, University of Science and Technology Beijing in 1991, and a post-doctoral fellow in the School of Materials Engineering, University of Science and Technology Beijing from 1991 to 1993. He obtained the title of associate professor in 1992. In 2000, he was qualified as a registered engineer in Canada. Since 2002, he has been the manager of the PFC R & D department of Magna Engine and Transmission Group. In 2008-2009, he participated in the "Innovation and Management" full-time training hosted by the University of Toronto, Canada, and obtained a master's degree.
Since 2011, he has been the chief researcher of Baosteel Research Institute; since 2017, he has been the chief chief of automotive materials and technology of Guangzhou Automobile Research Institute. In September 2018, he was the chief technical expert of Beijing Shougang Co., Ltd., responsible for grasping the development trend of automotive materials technology and formulating new materials And medium- and long-term development plans for the application of automotive parts and materials, the establishment of a complete EVI system and a technical service support system.